Concentrations of IPSO25 in surface sediments from coastal and near-coastal Antarctic locations ...

• Main Authors: Belt, Simon T, Smik, Lukas, Brown, Thomas A, Kim, Jung-Hyun, Rowland, Steve J, Allen, Claire Susannah, Gal, Jong-Ku, Shin, Kyung-Hoon, Lee, Jae Il, Taylor, Kyle W R
• Format: Dataset
• Language: English
• Published: PANGAEA 2016
• Subjects: Campaign of event; Location of event; Event label; Optional event label; Date/Time of event; Latitude of event; Longitude of event; Elevation of event; DEPTH, sediment/rock; Ice Proxy for the Southern Ocean with 25 carbon atoms per unit sediment mass; Giant box corer; Gas chromatography - Mass spectrometry GC-MS; ANT-II/3; ANT-III/3; ANT-IV/2; ANT-IV/3; ANT-IV/4; ANT-VI/2; ANT-VI/3; ANT-VIII/5; ANT-VIII/6; ANT-IX/3; Polarstern; Antarc*; Antarctic; Ice Shelves; Sea ice; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.864502; https://doi.pangaea.de/10.1594/PANGAEA.864502

The presence of a di-unsaturated highly branched isoprenoid (HBI) lipid biomarker (diene II) in Southern Ocean sediments has previously been proposed as a proxy measure of palaeo Antarctic sea ice. Here we show that a source of diene II is the sympagic diatom Berkeleya adeliensis Medlin. Furthermore, the propensity for B. adeliensis to flourish in platelet ice is reflected by an offshore downward gradient in diene II concentration in >100 surface sediments from Antarctic coastal and near-coastal environments. Since platelet ice formation is strongly associated with super-cooled freshwater inflow, we further hypothesize that sedimentary diene II provides a potentially sensitive proxy indicator of landfast sea ice influenced by meltwater discharge from nearby glaciers and ice shelves, and re-examination of some previous diene II downcore records supports this hypothesis. The term IPSO25-Ice Proxy for the Southern Ocean with 25 carbon atoms-is proposed as a proxy name for diene II. ... : Supplement to: Belt, Simon T; Smik, Lukas; Brown, Thomas A; Kim, Jung-Hyun; Rowland, Steve J; Allen, Claire Susannah; Gal, Jong-Ku; Shin, Kyung-Hoon; Lee, Jae Il; Taylor, Kyle W R (2016): Source identification and distribution reveals the potential of the geochemical Antarctic sea ice proxy IPSO25. Nature Communications, 7, 12655 ...